Automatic trimmer foot



June 26, 1951 s GARClA 2,558,353

AUTOMATIC TRIMMER FOOT Filed Feb. 17, 1948 2 Sheets-Sheet 1 I N VEN TOR.

Salvador G Gamia ATTD RN EYS June 26,1951 s. G.- GARCIA 2,553,353

AUTOMATIC TRIMMER FOOT Filed Feb. 17, 1948 2 Sheets-Sheet 2 $1 .51Jiyfi.

I N VEN TOR.

J'a Zz ador 6: Garcia ATTU RN EYS Patented June 26, 1951 AUTOMATICTRIMMER FOOT Salvador G. Garcia, Swansea, Mass, assignor to Norman M.Zalkind, Fall River, Mass.

Application February 17, 1948, Serial No. 8,924

2 Claims.

This invention relates to the shoe at the lower end of the pressure barof sewing machines and in particular an improved pressure foot in whicha thread cutting knife is incorporated wherein as one piece of materialleaves the machine and another enters the chain of thread from thematerial leaving the machine will be automatically out leaving acomparatively short piece extending from the material as it leaves themachine.

The purpose of this invention is to eliminate the necessity of sewingmachine operators picking up a pair of shears and cutting the thread ofmaterial being stitched as the material leaves the machine.

Various types of attachments have been provided for severing the threadof sewing machines but these require changes in the machines or severthe thread too close to the material which often causes damage to thegoods and for these reasons devices for this purpose are not universallyused. With this thought in mind this invention contemplates a trimmerfoot or shoe for sewing machines which replaces the usual foot and isprovided with shearing knives that automatically sever the chain ofthread a shortdistance from the stitched material as it leaves themachine.

The object of this invention is, therefore, to provide a trimmer footfor sewing machines that replaces the usual presser foot and thatautomatically cuts the chain of thread a short distance from goodsstitched on the machine as additional material is inserted in themachine.

Another object of the invention is to provide thread cutting means in apressure foot of sew- 3 ing machines that is actuated by material fed tothe machine.

Another object of the invention is to provide a trimmer foot for sewingmachines for severing a chain of thread a short distance from materialstitched on the machine which may be readily installed on machines nowin use.

A further object of the invention is to provide an improvedautomatically operative trimmer foot for sewing machines for severingthe chain of thread which is of a simple and economical construction.

With these and other objects and advantages in view the inventionconsists of the new and novel combination, construction, and arrangementof parts as hereinafter more fully described, set forth in the claimsappended hereto, and disclosed in the accompanying drawings forming parthereof, wherein:

Figure 1 is a view showing a front elevation of the head of a sewingmachine with parts omitted and with'the improved trimmer foot installedon the lower end of the presser-bar.

Figure 2 is a plan view taken on line 2-2 of Figure 1 with theneedle-bar and presser-bar omitted, illustrating the trimmer footpositioned above the feed dog and needle plate.

Figure 3 is a longitudinal section through the trimmer foot with partsbroken away and parts omitted, showing the lever knife dropped downwardbetween two pieces of material.

, Figure 4 is a view showing an end elevation of the presser-bar withthe trimmer foot shown in section illustrating the thread grippingfinger at the end of the lever knife.

Figure 5 is a view showing a side elevation of the trimmer foot withpart broken away showing the stationary cutter blade.

Figure 6 is a plan view of the trimmer foot showing the relativepositions of the parts.

Figure 7 is a similar view looking upward toward the under surfacethereof.

Figure 8 is a View showing a side elevation of the trimmer footillustrating stitched pieces of material leaving the machine and piecesof material to be stitched entering the opposite end of the trimmerfoot.

Figure 9 is a detail showing a section taken on line 9-9 of Figure 6showing the spring for actuating the lever knife.

Figure 10 is a detail illustrating the lever knife. Figure 11 is adetail showing the stationary knife.

Referring now to the drawings wherein like reference characters denotecorresponding parts the improved trimmer foot of this invention includesa foot or shoe in mounted on ashank II and provided with a lever knife12 and a stationary knife blade I3.

The trimmer foot I0 or shoe is formed of a substantially solid bar withan arcuate toe M at the outer end and a shoulder formed withside walls I5 and I 511 at the opposite end and through which it is pivotallymounted on a downwardly disposed tongue l6 of the shank H by a pin IT.The end wall 18 of the shoulder is separated from the side walls thereofby vertically disposed slots l8 and 20. The shoe of the trimmer foot I0is provided with an L-shaped slot having a longitudinally positionedpart 2| and a transverse section 22, and the L-shaped lever knife l2which is provided with a long arm and a short arm is positioned in theslotwith the small end of the long arm thereof pivotally mounted in theshoe on a pin 23. The small end of the lever knife is provided with anextending finger 24 by which this end is urged upward and the oppositeend downward by a spring 25, as shown in Figure 9.

The opposite end of the lever knife I2 is provided with a shearingflange 26 having a thread gripping finger 21 with an arcuate lower edgeformed at the lower end thereof providing a thread holding slot 28 abovethe finger. The flange 26 is positioned, in the transverse section 22 ofthe slot in the trimmer foot and the long side of the lever knife isformed with an arcuate. lower edge 29 which, when the lever knife isdropped downward, as shown in Figures 3 and 8, extends below thematerial being stitched so that the finger 21 may ride over the chain ofthread until the thread snaps into the slot 28. With the thread in theslot 28. the next material to be stitched as indicated by the numeral 3engages the arcuate lower surface 29 of the lever knife l2- and forcesthe knife upward against the spring 25 so that the flange 2!; slidesagainst the sharp edge 3| ofthe stationary knife l3 thereby shearing thethread. The knife I3 is mounted on a pin 32 in the end wall IQ of theshoulder of the trimmer foot and the knife is resiliently urged outwardby a spring 33 also positioned in the end i8, as illustrated in Figure5.

With the parts arranged in this manner the trimmer foot is carried bythe presser-bar 34 with the needle-bar 35 positioned as shown in Figure1, and the trimmer foot ill holds layers of material to be stitchedagainst the feed dog 35 on the needle plate 31, and after the material38 is stitched a chain of thread 39 will extend from the rear edge 43thereof, and the chain of thread will be picked up by the finger '2? ofthe lever knife 12, as shown in Figure 8, wherein the thread will beautomatically servered at the point 44, leaving a short piece of threadat the edge of the material. The thread is severed at a point betweenthe edgeof the stitched material and the needle opening 42 in thetrimmer foot, as illustrated in Figure 8 wherein a short piece of threadwill be provided at the leading edge of the material entering themachine.

It will be understood that although this attachment is illustrated asmounted on the presser-bar it may be attached to any suitable part of asewing machine where it will sever the thread, and although it is shownas a single unit it may be used in multiple wherein it is adapted foruse with gang sewing machines and machines having a plurality ofneedles.

It will be understood that modifications may be made in the design andarrangement of the parts without departing from the spirit of theinvention.

What is claimed is:

1. In a sewing machine attachment, a trimmer foot adapted to be carriedby the presser-bar of the machine, said trimmer foot having an L- shapedslot therethrough and a shoulder at one end, a knife fixedly mounted onthe shoulder, means resiliently urging the cutting edge of the knifeoutward, an L-shaped lever knife positioned in the slot with the shortleg thereof positioned to coact with the knife, said short leg having anarcuate thread gripping finger formed on the lower edge with a threadholding slot above the finger, means pivotally mounting the said leverknife in the slot of the trimmer foot, and resilient means urging theend of the lever knife carrying the thread gripping finger downward,said lever knife having an arcuate lower edge.

2. In a thread cutting attachment for a sewing machine, a pressure bar,a shoe having a vertically disposed L-shape slot therethrough with thelong section of the slot extended longitudinally of the shoe and withthe short section extended transversely and spaced from one endproviding an end wall, means mounting the shoe on the said pressure bar,a knife bladepositioned in the shoe and mounted on the said end wallwith the cutting edge extended from said wall, an L-shape lever knifehaving a long arm and a short arm in the shoe and mounted with the shortarm positioned to coact with the knife blade to shear thread positionedbelow the shoe as the lever knife moves upwardly said short arm of theL- shaped lever knife having an arcuate thread receiving slot thereinfor picking up thread below the shoe and carrying the thread upwardlyagainst the cutting edge of the knife blade, and means pivotallymounting the said lever knife, through the long arm thereof in the shoe,said lever knife positioned whereby as material stitched by the machineleaves the shoe the lever knife drops downwardly and as material passesunder the shoe the lever knife is actuated upwardly by the material tocoact with the knife blade in the shoe to shear the thread.

SALVADOR G. GARCIA.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,376,417 Chudner May 22, 19452,423,001 Blowers June 24, 1947

